Disposable diapers of the children's training pant type, or of the adult incontinence type, are typically equipped with elastic strands, which generally encircle the waistband area and leg-holes. These strands of elastic are typically captured with adhesive between two layers of nonwoven materials. Various methods are used to position these elastic strands so that they produce the desired effect in the desired areas.
Several methods of cutting elastic strands in diaper manufacturing exist. One method of cutting the strands is to sever them ultrasonically, as described in U.S. Pat. No. 5,660,657. As taught in U.S. Pat. No. 5,707,470, an ultrasonic device can be used to sever elastic members, while the carrier webs that encapsulate the elastics are left intact.
One problem associated with prior art severing lies in the tendency of the unsecured severed ends of elastic to retract to some point beyond the limits of any adhesive pattern that is used to anchor the elastic strands to their carriers. Thus, the elastic strands are not controlled or anchored near the ends of the adhesion pattern and may snap back further into the adhesive pattern than desired. This results in an incomplete elastic pattern and poor product characteristics.
The problem remains of efficiently and securely placing elastic in the undergarment in such a manner that the elastic is still effective after severing the elastic. Securing elastic strands around the back and front waists, for example, in a secure and systematic manner is conducive to high speed manufacturing associated with diaper manufacturing.